Time Delay Mechanism for a Hydraulic Drug Delivery Device

Abstract

A medicament delivery device may comprise a medicament chamber configured to hold a medicament, a plunger configured to move relative to the medicament chamber to expel the medicament from the medicament chamber, a pin configured to move from a first pin position wherein the pin prevents movement of the plunger to a second pin position wherein the pin allows movement of the plunger, an actuation assembly configured to move the pin from the first pin position to the second pin position, and a needle coupled to the medicament chamber. The medicament may flow through the needle from the medicament chamber to a user. The actuation assembly may be configured to automatically move the pin after a predetermined time delay.

1 - 11 . (canceled) 
     
     
         12 . A medicament delivery device comprising:
 a first chamber including a first plunger, the first plunger configured to move relative to the first chamber;   a second chamber fluidly connected to the first chamber, the second chamber configured to receive fluid from the first chamber when the first plunger moves relative to the first chamber;   a third chamber including a third plunger, the third chamber fluidly connected to the first chamber, wherein the third chamber is configured to contain a medicament, the third plunger configured to move relative to the third chamber when the first plunger moves relative to the first chamber;   a biasing element configured to move the first plunger relative to the first chamber; and   a needle coupled to the third chamber, the needle configured to provide a pathway for the medicament to flow from the third chamber to a user as the third plunger moves relative to the third chamber.   
     
     
         13 . The medicament delivery device of  claim 12 , wherein the first chamber is configured to receive a fluid, wherein at least a portion of the fluid is transferred from the first chamber to the second chamber as the first plunger moves relative to the first chamber. 
     
     
         14 . The medicament delivery device of  claim 13 , wherein at least a portion of the fluid is transferred from the first chamber to the third chamber as the first plunger moves relative to the first chamber. 
     
     
         15 . The medicament delivery device of  claim 14 , wherein the medicament delivery device is configured to transfer the fluid from the first chamber to the second chamber before the fluid is transferred from the first chamber to the third chamber. 
     
     
         16 . The medicament delivery device of  claim 14 , wherein the medicament delivery device is configured such that there is a time delay between a time when first piston begins to move relative to the first chamber and the third piston begins to move relative to the third chamber. 
     
     
         17 . The medicament delivery device of  claim 14 , wherein the first plunger includes a first collar having a first collar diameter and a body having a body diameter, wherein the body diameter is less than the first collar diameter. 
     
     
         18 . The medicament delivery device of  claim 17 , wherein the first plunger includes a second collar having a second collar diameter, wherein the body diameter is less than the second collar diameter. 
     
     
         19 . The medicament delivery device of  claim 18 , wherein the first chamber includes a distal portion between a distal end of the first chamber and the first collar,
 wherein the first chamber includes a proximal portion between the first collar and the second collar, and   wherein the fluid flows from the distal portion through the bypass and into the proximal portion as the first plunger moves relative to the first chamber.   
     
     
         20 . The medicament delivery device of  claim 13 , wherein the second chamber includes a second plunger configured to move relative to the second chamber as the fluid is transferred from the first chamber to the second chamber. 
     
     
         21 . The medicament delivery device of  claim 13 , wherein the second chamber includes a flexible membrane configured to move relative to the second chamber as the fluid is transferred from the first chamber to the second chamber. 
     
     
         22 . The medicament delivery device of  claim 13 , wherein the second chamber includes a gas permeable membrane configured to allow gas to escape from the second chamber but prevent fluid from exiting the second chamber as the fluid is transferred from the first chamber to the second chamber. 
     
     
         23 . The medicament delivery device of  claim 12 , wherein the transfer of the fluid into the third chamber moves the third plunger relative to the third chamber thereby expelling the medicament from the third chamber through the needle and to the user.